Safety ski binding

ABSTRACT

Safety ski binding with delayed release. There is provided a delayed release device for a safety ski binding, applicable to either the toe or heel component thereof, wherein release is momentarily delayed by a dash-pot type device but valving is provided which permits rapid return to normal condition. Movement of the binding part in release direction is opposed both by the usual adjustable resilient means and also by the dash-pot type device which momentarily delays release to a point slightly above the force level for which release has been set. The dash-pot device is provided with valving effecting a delayed action in a binding release direction with a rapid return to the normal condition.

United States Patent [1 1 Svoboda 1 SAFETY SKI BINDING [75] Inventor: Josef Svoboda, Schwechat, Austria [73] Assignee- Gertsch AG, Zug, Switzerland [22] Filed: May 28, 1974 [21] Appl. No.: 474,040

[30] Foreign Application Priority Data May 30, 1973 Austria 4786/73 [52] US. Cl 280/l1.35 T [51] Int. Cl. A63c 9/08 [58] Field of Search 280/1135 T [56] References Cited UNITED STATES PATENTS 3,348,855 10/1967 Marker 280/1135 T 3,350,110 10/1967 Salomonm. 280/1135 T 3,528,673 9/1970 Myerson 280/1135 T 4 1 July 8,1975

Primary Examiner-Robert R. Song Attorney, Agent, or FirmWoodhams, Blanchard and Flynn [57] ABSTRACT Safety ski binding with delayed release. There is provided a delayed release device for a safety ski binding, applicable to either the toe or heel component thereof, wherein release is momentarily delayed by a dash-pot type device but valving is provided which permits rapid return to normal condition. Movement of the binding part in release direction is opposed both by the usual adjustable resilient means and also by the dash-pot type device which momentarily delays release to a point slightly above the force level for which release has been set. The dash-pot device is provided with valving effecting a delayed action in a binding release direction with a rapid return to the normal condition.

8 Claims, 6 Drawing Figures SAFETY SKI BINDING FIELD OF THE INVENTION The invention relates to a safety ski binding, in which binding elements, as sole or heel holders, are provided with locking mechanisms which lock to a predetermined level of release force the element in its effective position and upon the exceeding of said force then release the element for movement out of effective position together with a retarding device which retards the release movement of the locking member for a short time up to a force level higher than the normal release force, wherein the retarding device is a spring-loaded pneumatic damping cylinder.

BACKGROUND OF THE INVENTION Such a safety ski binding is known from German Offenlegungsschrift No. 1 578 861. In this known construction, wherein the cylinder is closed at one end by a plug and at the other end by an air-tight piston, the spring lies in the cylinder between the plug and the pis' ton. The piston has a passage into which a throttle part extends in the upper stroke zone of the piston and the locking element is supported against the piston.

However, this known construction has the disadvantage that the throttle opening is constricted in the first zone of movement of the piston. The constructions of such throttle openings are already difficult, and it is yet more difficult to manufacture a throttle opening with a constricted cross section. Throttle openings of this type have, as is known, a diameter of approximately 0.1 mm. A further disadvantage of the known construction lies in that for the retardation and return the same throttle opening is used which results in the return taking as much time as the retarding stroke. Since the time required for the retarding stroke must be ample for its purpose and return, contrastingly, should be carried out quickly, it is not possible to meet both requirements with a single throttle opening.

It has become known from a hydraulic retarding device to use two throttle openings, see for example German Offenlegungsschrift No. 1 578 901. However, the larger throttle opening is herein arranged in the same manner in the retarding device as the first throttle opening. Thus the desired objective, namely the quick return, cannot be achieved here.

Hence, the objective of the invention is to produce a retarding device of the type mentioned above in which a quick return is obtained and in addition provision is made for a device with variable volume and/or open piston.

SUMMARY OF THE INVENTION According to the invention the desired goal is achieved by constructing the piston as a second pneumatic cylinder which has at least one opening which cooperates, if necessary, with a closure element, wherein the closure element preferably contains a throttle opening.

This objective is easily achieved by the inventive construction. The safety ski binding of the invention is thus equipped with a retarding device which can be operated on atmospheric pressure and through this an excessive pressure and the difficulties connected therewith are avoided.

According to a preferred embodiment of the inven tion the closure element can be constructed as a valve guided in a cylindrical body which also serves as a piston. The closure part of such valve is a hemisphere provided with a throttle opening and the seat of which valve is the opening provided in the cylinder.

This construction permits the inner chamber of the cylinder, depending upon the operation of the cylinder piston, to be connected either through only the throttle opening or both through the throttle opening and also through the first opening of the cylinder to the remaining chamber of the retarding device. Depending upon whether the valve closes or opens, the flow between inner chamber and compensating chamber is slow or rapid.

According to a further characteristic of the invention it is possible to provide inside of the cylinder piston a further air-tight piston which can be adjusted in the direction of movement of the piston by means of an adjusting mechanism, such as by a screw which is arranged in the piston rod.

This construction makes it possible to enlarge or reduce in size the inner chamber of the cylinder piston between the adjusting rings of the second piston. Thus, the retardation can be adjusted automatically.

According to yet a further inventive characteristic, the rearward end of the cylinder piston can be opened by at least one further throttle opening which can be closed, preferably by a valve. Through this construction it is possible to use the respective chamber which is provided behind the cylinder piston as an inner chamber".

A further characteristic of this embodiment consists in that in the rear wall portion two throttle openings of variable cross section are provided, of which the larger one is provided with a valve which closes in the direction of movement of the retarding device. This construction has the advantage that the closure plate of the cylinder piston can be mounted with the valve separately and the front end with the passage opening is mounted thereafter on the piston part.

The present embodiments have received the spring within the compensating chamber. According to a further embodiment of the invention, the spring can be arranged outside of the compensating chamber, in which case the piston rod is equipped with a disk which serves as a spring washer. This construction has the advantage that the inner chamber is not then used by the spring and the piston with the two passage openings can simply be mounted into the cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described more in detail in connection with the drawings which illustrate various exemplary embodiments of the subject matter of the invention.

In the drawings:

FIG. 1 is a cross-sectional top view of the safety ski binding of the invention,

FIGS. 2 and 3 illustrate in an enlarged scale the retarding device for FIG. 1 in two positions,

FIG. 4 illustrates a retarding device with a variable inside space,

FIG. 5 illustrates an embodiment with a rearwardly open cylinder piston, and

FIG. 6 illustrates a retarding device with a spring which is arranged outside of the cylinder piston.

DETAILED DESCRIPTION As shown in FIG. 1, two bent-leverlike sole holders 1 and 2 are supported pivotally about the axes 3. Each bent leverlike sole holder carries on one arm two, at least approximately vertical, pins 4, 5 on which rollers 6, 7 are rotatably supportedv The ski boot 8 which is indicated only by dash-dotted lines is supported with its front zone on the rollers 7, the axes of which are spaced less from one another than the axes 3 of the sole holders I, 2. Through this a moment is created which tends to pivot the sole holders 1, 2 about the axes 3 inwardly so that the rollers 6, 7 which are provided at the ends of the arms I bear more firmly on the ski boot.

The arms 2 of the sole holders 1, 2 rest on a slide I0 or the like which is under the effect of a spring 9. The spring 9 is simultaneously a part of the retarding device II which will be described in detail below. The boot 8 is further held in its base position by a clamping means which is illustrated by a dash-dotted line. The clamping means 15 is pivotal about an axis 16 and is ar ranged adjustably in elevating direction by means of a screw 17 to adapt same to boot soles of various thicknesses. The entire safety binding is mounted onto the ski I8 by interpositioning a stepping plate 19 by means of screws 20.

The retarding device has, as is illustrated in an enlarged scale in FIGS. 2 and 3, a fixed cylinder 21 in which a cylinder piston 22 is arranged movably by means of a piston rod 23 against the force of the spring 9 in the longitudinal direction of the cylinder 21. The cylinder piston 22 has at its front end an opening 24 which can be closed or opened by means of a valve 25. In the exemplary embodiment of FIGS. 1 to 3, the valve 25 consists of a guide frame 26 which is movably arranged on the front end of the cylinder piston 22 and is equipped with a hemispherical closure element 27 which contains a throttle opening 28. The throttle opening 28 is substantially smaller in relationship to the passage opening 24. The end 103 of slide 10 bears against the free end of piston rod 23 whereby a rightward, as seen in FIG. 1, movement of the slide 10 will be opposed by the spring 9.

If one of the sole holders 1, 2 is now swung from its rest position by the appearance of outside forces acting onto the ski boot 8, the arm 2 of the sole holder 1, 2 presses onto the slide 10 and thence through the piston rod and through the retarding device onto the spring 9. The cylinder piston 22 moves thus in the direction of the spring 9 and the valve 25 closes the passage opening 24. In this manner the air can only slowly move from the equalizing chamber 30 into the inner chamber 29. In this manner, if only small forces occur which do not stress the foot or the ankle to a dangerous degree, as for example to the likelihood of a fracture, an additional resistance is first created by compression of the air present in the compensating chamber 30 which slows the movement of the slide 10. If such forces are removed before the ski binding would have released and thus the stress on the ski boot 8 is removed, then the spring 9 presses the cylinder piston 22 back into its original position, whereby the valve 25 opens the passage 24 of the cylinder piston 22 and the air flows quickly back from the inner chamber 29 into the compensating chamber 30.

According to FIG. 4 a further piston 31 is positioned in the cylinder piston 22, which piston 31 has inside of the piston rod 23 a piston rod which is constructed as an adjusting screw 32. The construction and operation of the valve 25 corresponds to the construction according to FIGS. 1 to 3. By using the second piston 31, the volume of the inner chamber 29 of the cylinder piston 22 can be regulated. If the adjusting screw 32 is adjusted in the piston rod 23 toward the front end of the piston cylinder 22, the inner chamber 29 becomes smaller and through this the relationship between inner chamber and compensating chamber becomes smaller. This situation causes the rate of the retardation to become steeper.

According to FIG. 5 a cylinder piston 29' is provided which hsa two openings 33 and 34 at its rearward end. The passage 24 is here open, namely without a valve. Instead, a valve closes the larger throttle opening 34, whereby the smaller throttle opening 33 similar to the throttle opening 28 of the valve 25 is always open. The entire arrangement is stored in the rear piston part 36. The operation of this construction corresponds sub stantially to the aforementioned one with the exception that the inner chamber 29 has a small volume and the remaining part of the inner chamber is provided in the form of a rear chamber 29". The advantages of this embodiment have already been discussed above in the general portion of the description.

In the construction of FIG. 6, the spring 9 is arranged outside of the cylinder 21. This makes it possible, at an equally large volume of the compensating chamber 30, to diminish the size of the cylinder 2]. In this embodiment the piston operates in a manner generally similar to the piston 36 in FIG. 5. The piston rod 23' is provided in this case with a disk 37 which serves as a spring washer. The operation of this construction corresponds to the already discussed embodiments.

The invention is not limited to the described exemplary embodiments. Various further variations exist which lie within the scope of the claims. Thus it is for example possible to combine along one another the embodiments according to FIGS. 1 to 2 or 4 to 6. Also it is possible that, for the purpose of showing the adjusting force, a conventional indicating mechanism be provided in the safety ski binding and coupled with the spring 9. It is also possible to use the described retarding device in connection with ski bindings of different types.

Although particular preferred embodiments of the invention have been disclosed above for illustrative purposes, it will be understood that variations or modifications thereof which lie within the scope of the appended claims are fully contemplated.

The embodiments of the invention in which an exclusive property or privilege is claimed as follows:

I. In a safety ski binding having a binding element with locking means which lock to a predetermined normal level of force said binding element in an effective position and upon exceeding said predetermined normal level of force release said binding element for a movement out of said effective position and retarding means for retarding a release movement of said locking means to a force level higher than a normal release force, said retarding means being defined by a pneumatic damping first cylinder having reciprocal piston means therein biased to one end of said first cylinder by a spring, the improvement comprising wherein said piston means includes means defining a pneumatic second cylinder having means defining at first opening therein. a closure element mounted for movement into and out of engagement in said first opening and means defining a throttle second opening for restricting the movement of gas therethrough, said closure member permitting no gas movement through said first opening in one direction but permitting gas flow therethrough in the other direction.

2. The improvement according to claim 1, wherein said closure element is a valve member which is guided for movement on said piston means, said valve member having a hemisphere surface provided thereon and having said throttle opening therethrough, said valve member being movable into a seating relation with said first opening.

3. The improvement according to claim 1, wherein said piston means includes a further air-tight piston inside said second cylinder and adjusting means for adjusting the position of said air-tight piston within said second cylinder.

4. The improvement according to claim 1, wherein said spring is arranged outside of said first cylinder and wherein a piston rod secured to said piston means has a disk thereon which serves as a spring washer.

5. The improvement according to claim 1, wherein said second opening is mounted in said closure member.

6. The improvement according to claim I, wherein said second cylinder has a pair of spaced walls, one wall having an opening therethrough providing communication between said first and second cylinders, the other wall having said first and second openings therethrough and said closure member mounted thereon.

7. The improvement according to claim 6, wherein said first and second openings are of different cross sections, the larger one of said openings having said closure member mounted in cooperation therewith.

8. The improvement according to claim I, wherein said spring is mounted in said first cylinder and engages said piston means to bias said piston means to said one end of said first cylinder. 

1. In a safety ski binding having a binding element with locking means which lock to a predetermined normal level of force said binding element in an effective position and upon exceeding said predetermined normal level of force release said binding element for a movement out of said effective position and retarding means for retarding a release movement of said locking means to a force level higher than a normal release force, said retarding means being defined by a pneumatic damping first cylinder having reciprocal piston means therein biased to one end of said first cylinder by a spring, the improvement comprising wherein said piston means includes means defining a pneumatic second cylinder having means defining at first opening therein, a closure element mounted for movement into and out of engagement in said first opening and means defining a throttle second opening for restricting the movement of gas therethrough, said closure member permitting no gas movement through said first opening in one direction but permitting gas flow therethrough in the other direction.
 2. The improvement according to claim 1, wherein said closure element is a valve member which is guided for movement on said piston means, said valve member having a hemisphere surface provided thereon and having said throttle opening therethrough, said valve member being movable into a seating relation with said first opening.
 3. The improvement according to claim 1, wherein said piston means includes a further air-tight piston inside said second cylinder and adjusting means for adjusting the position of said air-tight piston within said second cylinder.
 4. The improvement according to claim 1, wherein said spring is arranged outside of said first cylinder and wherein a piston rod secured to said piston means has a disk thereon which serves as a spring washer.
 5. The improvement according to claim 1, wherein said second opening is mounted in said closure member.
 6. The improvement according to claim 1, wherein said second cylinder has a pair of spaced walls, one wall having an opening therethrough providing communication between said first and second cylinders, the other wall having said first and second openings therethrough and said closure member mounted thereon.
 7. The improVement according to claim 6, wherein said first and second openings are of different cross sections, the larger one of said openings having said closure member mounted in cooperation therewith.
 8. The improvement according to claim 1, wherein said spring is mounted in said first cylinder and engages said piston means to bias said piston means to said one end of said first cylinder. 